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integrated river basin management in rapidly urbanizing areas:a case of Shenzhen,China

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Frontiers of Environmental Science & Engineering 2011年第2期5卷 243-254页

作者： Lei liu Xiaoming MA College of Environmental Sciences and Engineering Peking UniversityBeijing 100871China

The rapid urbanization of China is causing a burden on their water resources and hindering their sustainable *** paper analyzes effective methods to integrated river basin management(iRBM)using Longgang River basin of Shenzhen as an example,w.ich is the city with the fastest rate of urbanization in China and even the whole *** the past 20 years,China has undergone a population boom due to the increase of immigrant workers and rapid development of laborintensive industries,w.ich led to the sharp increase of water consumption and sewage ***,the construction of the water infrastructure is still lagging far behind the environmental and social development,with only 32.7%of sewage in the district being ***,every water quality indicator of the Longgang River basin was unable to meet the required corresponding environmental standards,w.ich further aggravated the water shortages of the ***,an analytical framework is proposed to address the iRBM of the study *** problems with the current management system include the lack of decentralization in decision-making,lack of enforcement with redundant plans,weak management capacity,financial inadequacy,and a poor system of stakeholder *** light of the principles of iRBM and the situation of the region,corresponding measures are put forward,including an increase of power given to sub-district offices,fewer but more feasible plans,capacity building among stakeholders,a combination of planning and marketing for overcoming financial inadequacy,and profound reform in the public participation *** framework and institutional suggestions could inform similar processes in other representative river basins.

关键词： integrated river basin management(iRBM)model Longgang River basin Shenzhen decentralization stakeholder participation

STABiLiZATiON FOR A CLASS OF LARGE-SCALE STOCHASTiC NONLiNEAR SYSTEMS wiTH DECENTRALiZED CONTROLLER DESiGN

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Journal of Systems Science & Complexity 2007年第1期20卷 127-134页

作者： Xiaowu MU Haijun liu Department of Mathematics Zhengzhou University Zhengzhou 450052 China

in this paper, a state feedback adaptive stabilization for a class of large-scale stochastic nonlinear systems is designed with Lyapunov and Backstepping method. in the systems there are uncertain terms, whose bounds are governed by a set of unknown parameters. The designed controllers would make the close-loop systems asymptotically stable and adaptive for the unknown parameters. As an application, a second order example is delivered to illustrate the approach.

关键词： Adaptive stabilization backstepping large-scale systems stochastic nonlinear systems

ELASTiC-PLASTiC DYNAMiC RESPONSE OF A CANTiLEVER BEAM SUBJECTED TO OBLiQUE iMPACT AT iTS TiP

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Acta Mechanica Solida Sinica 2005年第4期18卷 316-325页

作者： Xi Feng liu Feng Shandong institute of Architecture and Engineering Jinan 250101 China

By employing large deformation governing equations expressed in the form of finite difference, the dynamic responses of an elastic, perfectly plastic cantilever subjected to an oblique impact at its tip was numerically studied. Through analyzing the instantaneous distribution of the yield function （φ = ｜M/Mo｜＋（N/No）^2）, bending moment and axial force during the early stage of the response, the elastic-plastic deformation mechanism and the influence of axial component of an oblique impact on the dynamic response of a cantilever beam were discussed. The present analysis shows that the deformation mechanism of an elastic-plastic cantilever subjected to an oblique impact consists of four phases, i.e. ‘the expanding compressed plastic region＇ mode; the ‘generalized traveling plastic hinge＇ and ‘shrinking plastic region＇ mixed mode; the ‘stationary plastic hinge＇ mode and ‘elastic vibration＇ mode. Compared with the two-phase deformation mode obtained by using the rigid, perfectly plastic approach, the mode of shrinking plastic region that occurred instantly after the oblique impact and the mode of stationary hinge were both confirmed. The primary features of the deformation mechanism are captured by both analysis methods. it has also been found that the beam＇s deformation is mainly controlled by the axial component of the oblique impact in the early phase of the dynamic response, the deformation mechanism is obviously different from the case of a transverse impact. with further development of the response, the axial component attenuates rapidly and gives negligible contribution to the yielding of the beam cross-section. At the same time, the bending moments along the cantilever develop gradually and dominate the beam＇s deformation. The numerical results indicate that the mass, impact speed and oblique angle are the important factors that influence the elastic-plastic dynamic response of a cantilever beam.

关键词： oblique impact elastoplasticity large deformation dynamic response cantilever

Entropy-expansiveness of Geodesic Flows on Closed Manifolds without Conjugate Points

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Acta Mathematica Sinica,English Series 2016年第4期32卷 507-520页

作者： Fei liu Fang wANG College of Mathematics and System Science Shandong University of Science and Technology Qingdao 266590 P. R. China School of Mathematical Sciences Capital Normal University Beijing 100048 P. R. China Beijing Center for Mathematics and information interdisciplinary Sciences (BCMiiS) Beijing 100048 P. R. China

in this article,we consider the entropy-expansiveness of geodesic flows on closed Riemannian manifolds without conjugate *** prove that,if the manifold has no focal points,or if the manifold is bounded asymptote,then the geodesic flow.is ***,for the compact oriented surfaces without conjugate points,we prove that the geodesic flows are *** also give an estimation of distance between two positively asymptotic geodesics of an uniform visibility manifold.

关键词： Entropy-expansiveness geodesic flows manifolds without conjugate points

Synthesis of MnxOy@C hybrid composites for optimal electromagnetic wave absorption capacity and wideband absorption

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Journal of Materials Science & Technology 2022年第8期103卷 157-164页

作者： Yue liu Xuehua liu Xinyu E Bingbing wang Zirui Jia Qingguo Chi Guanglei wu institute of Materials for Energy and Environment State Key Laboratory of Bio-fibers and Eco-textilesCollege of Materials Science and EngineeringQingdao UniversityQingdao 266071China Key Laboratory of Engineering Dielectrics and its Application Ministry of EducationSchool of Electrical&Electronic EngineeringHarbin University of Science and TechnologyHarbin 150080China

The fabrication of high-performance electromagnetic(EM)wave absorption(EMA)materials is an effective strategy to deal with ever-increasing EM *** this work,a series of manganese oxides/porous carbon(Mn_(x)O_(y)@C)hybrid composites are obtained by a two-step *** is revealed that different manganese oxides play various influence on the dielectric properties of *** to the moderate complex permittivity of MnO@C hybrid composites,the optimal reflection loss could reach as high as-76.0 dB at the matching thickness of 2.0 mm with 5.2 GHz of effective absorption bandwidth at thickness of 2.1 *** demonstrated that the addition of porous carbon is vital for enhancing EMA performance of composites,w.ich not only coordinates impedance matching allowing more EM waves enter the absorber,but also provides the path for electron movement,thus profiting conductive ***,different heterogeneous interfaces including porous carbon,manganese oxide and so on,are conducive to contribution of interface *** most noteworthy is ingenious design of composite materials and systematic research of EM energy attenuation mechanism in this work will provide the possibility to realize high-performance EMA.

关键词： Manganese oxide/carbon composites Dielectric loss Relaxation time Electromagnetic wave absorption

immobilization and characterization of the Lactarius deliciosus mycelia-embedded polylysine-alginate beads and their decolorization performance

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Frontiers of Chemical Science and Engineering 2023年第12期17卷 2001-2013页

作者： Yiwen Jin Jie Yuan Caixia liu Jiacheng Sun Youbin liu Zhifeng Ding Qingxi wu School of Life Sciences Anhui UniversityHefei 230601China Key Laboratory of Eco-engineering and Biotechnology of Anhui Province and Anhui Key Laboratory of Modern Biomanufacturing Hefei 230601China Department of Chemistry The University of Western OntarioOntario N6A 5B7Canada

Liquid fermented fungal mycelia with decolorization capability have potential applications in scale-up. in this work, the Lactarius deliciosus mycelia were immobilized on ε-polylysine-alginate beads, and the decolorization effects of ε-polylysine-alginate beads were demonstrated along with Coomassie brilliant blue G-250 as a model dye. Morphology observation confirmed the beads had an exterior film and interior capsule with honeycomb microstructures suitable for mycelia growth. it was manifested that the maximum decolorization efficiency for mycelia was 98.5% at a removal rate of 0.68 mg·L^(-1)·h after 3 days. in comparison, the decolorization efficiency of the immobilized mycelia reached the maximum value of 97.3% at a removal rate of 6.1 mg·L^(-1)·h after 8 h. The enzyme activities of lignin peroxidase and laccase tested in the immobilized mycelia were significantly higher than in that of the free ones, such as the lignin peroxidase had the highest enzyme activity of 77.6 ± 7.4 U·L^(-1) in the former, w.ile of 27.4 ± 8.7 U·L^(-1) in the latter. The immobilization of L. deliciosus mycelia could improve the decolorization of Coomassie brilliant blue G-250 efficiently. The prepared ε-polylysine-alginate beads embedded with L. deliciosus mycelia have very good reusability and a great potential in decolorizing analog dyes.

关键词： Lactarius deliciosus mycelia immobilization decolorization polylysine-alginate beads Coomassie brilliant blue G-250

Effect of sintering temperature in argon atmosphere on microstructure and properties of 3D printed alumina ceramic cores

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Journal of Advanced Ceramics 2020年第2期9卷 220-231页

作者： He Li Yongsheng liu Yansong liu Qingfeng ZENG Kehui HU Zhigang LU Jingjing LiANG Science and Technology on Thermostructural Composite Materials Laboratory Northwestern Polytechnical UniversityXi’anShaanxi 710072China NPU-SAS Joint Research Center of Advanced Ceramics Northwestern Polytechnical UniversityXi’anShaanxi 710072China Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China institute of Metal Research Chinese Academy of SciencesShenyang 110016China

Alumina ceramics with different sintering temperatures in argon atmosphere were obtained using stereolithography-based 3D *** effects of sintering temperature on microstructure and physical and mechanical properties were *** results show that the average particle size,shrinkage,bulk density,crystallite size,flexural strength,Vickers hardness,and nanoindentation hardness increased with the increase in sintering temperature,whereas the open porosity decreased with increasing sintering *** change was observed in phase composition,chemical bond,atomic ratio,and surface *** the sintered samples,the shrinkage in Z direction is much greater than that in X or Y *** optimum sintering temperature in argon atmosphere is 1350℃with a shrinkage of 3.0%,3.2%,and 5.5%in X,Y,and Z directions,respectively,flexural strength of 26.7 MPa,Vickers hardness of 198.5 HV,nanoindentation hardness of 33.1 GPa,bulk density of 2.5 g/cm^3,and open porosity of 33.8%.The optimum sintering temperature was 70℃higher than that sintering in air atmosphere when achieved the similar properties.

关键词： sintering temperature argon atmosphere alumina ceramics microstructure stereolithography

Analysis of minimum specific energy consumption and optimal transport concentration of slurry pipeline transport systems

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Particuology 2022年第7期20卷 38-47页

作者： Mingzhi Li Yanping He Ruhong Jiang Ji Zhang Hongsheng Zhang w.ihuang liu Yadong liu State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China institute of Marine Equipment Shanghai Jiao Tong UniversityShanghai 200240China CHEC Dredging Co. Ltd.Shanghai 200136China National Engineering Research Center of Dredging Shanghai 200120China

Slurry pipeline transport is widely used in several industrial *** the specific power consumption(SPC)and determining the best working conditions are important for the design and operation of transportation *** on the Shanghai Jiao Tong University high-concentration multi-sized slurry pressure drop(SJTU-HMSPD)pipeline-resistance-calculation model,the SJTU-SPC model for calculating the power required to transport a unit volume of solid materials over a unit pipeline length is established for a slurry transport *** said system demonstrates a uniformity coefficient in the 1.26–7.98 range,median particle size of 0.075–4 mm,particle volume concentration of 10–60%,and pipeline diameter of 0.203–0.8 *** results obtained were successfully verified against existing experimental *** influence of parameters,such as particle-gradation uniformity coefficient,median particle size,pipe diameter,and particle volume concentration,on the SPC were *** results revealed that the greater is the uniformity coefficient,the smaller is the minimum specific energy consumption and the larger the optimal transport concentration for a constant,median particle size *** observed,the optimal transport concentration for broad-graded sand equalled approximately 48%.These results supplement the conclusions of existing research,indicating that the optimal transport concentration is approximately 30%and provides theoretical support for high concentration transportation of broad graded slurry.

关键词： Slurry pipeline transport system Specific power consumption Minimum specific energy consumption Optimal transport concentration

Theoretical Simulation of the Vibrationally Resolved UV Absorption Spectrum of Acryloyl Fluoride

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Chinese Journal of Chemistry 2017年第5期35卷 733-741页

作者： Yuanyuan Cheng Yajun liu Key Laboratory of Theoretical and Computational Photochemistry Ministry of Education College of Chemistry Beijing Normal University Beijing 100875 China

Acryloyl fluoride is an ideal molecule for investigating the phenomenon of hindered internal *** concert with recently acquired high-resolution UV absorption spectrum of acryloyl fluoride,in this study,the absorption spectra of the s-trans and s-cis isomers of acryloyl fluoride were theoretically *** simulated spectra were convoluted by a Gaussian function with displacement,distortion,Franck-Condon,Herzberg-Teller,and Duschinsky effects in the framework of the time-independent *** statistical vibronic transition analysis reveals the unity of the spectrum transition property,the relevant normal modes,and the primary geometrical variations,enriching the understanding of the experimental *** discrepancy between the theoretical and experimental spectra was interpreted clearly.

关键词： acryloyl fluoride vibrational spectroscopy normal mode vibronic transition density functional calculations